Fluid pressure actuated motor



Patented Sept. 10,1940 a 2,213,948

UNITED STATES PATENT orrics 2,213,948 'r'wrn rnnssunn ACTUATEDMOTOBHerbert 0. Bowen, Detroit, Mich., asslgnor to Bydraulic Brake Company,Detroit, Mich, a corporation of California Application December 5, 1938,Serial No. 244,080 '1 Claims. (01. Gil-54.6)

This invention relates to brakes. and more parpassage 48 concentricallydisposed with relation ticularly to fluid pressure means for actuatingto both chambers. An inlet passage 48 adapted brakes. to be connected asby a conduit 50 to a suitable Broadly the invention comprehends a fluidsource of fluid pressure communicates with the I pressure actuated-motor operative to actuate passage 48, and a passage 52 providing acome I brakes in two phases, initially at low fluid presmunicationbetween the intake passage 48 and sure, and thereafter at relativelyhigh fluid presthe large chamber 44 is controlled as by a check surewithout proportionately greater applied opvalve 54. erating Iorce. Theend of the passage 46 opening into the An object of the invention is toprovide a chamber 44 is enlarged to provide an annular fluid pressureactuated motor operative in two shoulder, and seated on this shoulder isan anphases. nular washer 56. A shell 58 threaded in the en- Anotherobject of the invention is to provide larged end of the passage clampsthe annular a fluid pressure actuated motor including low washer on itsseat. This shell extends well into pressure actuated means, highpressure actuated the chamber 44, and the free end thereof. is 1 means,and pressure actuated means for render-- closed as by a head 60 providedwith a port 62, ing the lowpressure means ineffective during andsuitably arranged in the wall of the shell operation of the highpressure means. w is a port 64 providing a communication-between Otherobjects and advantages of the invention 1 the interior of the shell andthe chamber 44. will appear from; the iollowing'description taken Apiston 66 reciprocable in the shell 58 is seat 20 in connection with thedrawing forming a part ed on aheavy spring 68 interposed betweenthe ofthis specification, and in whichback of the piston and the head of theshell. A

Fig. l is a vertical sectional view of a brake rod Ill is mountedconcentrically in the head of taken just back of the head of the drum,illusthe piston, and a sealing cup 12 seated on the trating theinvention as applied; and head of the piston embraces the rod. The rod25 Fig. 2 is a sectional view substantially on line extends through theshell, the annular washer 2-2, Fig. 1. 56, and the passage 46 intothesmall chamber Referring to the drawing for more specific de- 42, and avalve 14 is carried by the rod for contails of the invention, I0represents a fixed suptrol of the communication between the passage portor backing plate. adapted to be secured to 46 and the shell. The valve14 is normally held 30 an axle or to an axle housing, and associatedwith on .a flexible seat 16 supported on the annular the backing plateis a rotatable drum l2 adapted washer 56. The rod also has thereonwithin to besecured to a wheel. the chamber 42 a valve 18 adapted'toseat on a The backing plate has suitably arranged there'- fiexiblewasher 80 on the bottom of the chamon a pair of spaced anchors l4 and i6and a ber 42. j

pair of adjustable retractile stops I8 and 20. A A piston 82reciprocable in the chamber 42 has pair of corresponding frictionelements or-shoes on its head a sealing cup 84. A light spring 86 22 and24 have their'articulate ends pivoted on interposed between the cup 84and the washer the anchors l4 and I6, and their force applying 80'serves to retain the cup andwasher 80 against ends normally rest on theadjustable stops I8 and displacement. The piston 82v also has a flange4o 20. The shoes are of conventional type, each in- 81 adapted to abutthe cylinder when he p cluding a web 26 supporting a rim 28 havingsetonis at rest so as to fix the retracted'position cured thereto afriction lining 3!! suitable for thereof, and arranged in the back ofthe piston is cooperation with the drum. a recess 88 for the receptionof the thrust pin A compound fluid pressure actuated motor 32 34, and adust shield 90 connects the thrust pin 45 slidably mounted on thebacking plate is c'onto the open end of the chamber 42. nected as bythrust pins 34 and 38 to the force A piston 92 reciprocable in thechamber 44 applying ends of the shoes, and a retractile spring has aconcentric recess 94 receiving the shell 38 connecting the shoesadjacent their force ap- 58, and a port 96 in the bottom of the recessso plying end servesto return the shoes upon comopens to the atmosphere.The piston 92'has on pletion of a braking operation to their retractedits head an annuar sealing cup 98 embracing the positions on the stopsl8 and 20. wall of the chamber and the shell 58, and the The motor 32includes a cylinder 40 having a cup is held against displacement by aspring I00 small chamber 42 and a relatively largechaminterposed betweenthe cup and the bottom of 5 her 44 communicating with one another as bya the chamber. The piston 92 alsdhas in its back 66 V t e fluid, thevalve 14 cracks and admits enters the passage 48, thence passes throughthe passage 46, past the valve 18, into the chamber 42, resulting in anincrease of pressure on the.

fluid in the chamber 42 and consequent movement of the piston 82 and thecylinder 40 in opposite directions. This movement of the piston and thecylinder efiectively moves the shoes 22 and 2 into engagement with thedrum l2.

Upon attaining a predetermined pressure1 or;

in der pressure into the shell 58, thence through t e port 64, into thechamber 44. As the pressure on the fluid in the shell 58 and the chamber44 builds up, the valve 18 moves to its seat and closes offcommunication between the chamber 42 and the passage 46. This results intrappingfluid in the chamber 42 and thereafter the-pressure on the fluidacting on the piston 66 and on the head of the valve 18 maintains thevalve 18 closed while the pressure on the fluid in the chamber 44acting, on the piston 92 causes further movement of the piston 92 andmovement of the cylinder 40 in the opposite direction, resulting in.

applying the shoes with increased force and less efiort on the part ofthe operator.

Upon concluding a braking operation, pressure on'the fluid is released,whereupon the valve 14 is urged to its seat by the spring 68, and thevalve 18 opens to establish communication between the chamber 42 and thepassage 46. This results in opening the chamber 42 directly to the inletpassage 48, and return of thefluid from the chamber 42 to the source ofsupply, and the fluid in the chamber 44 is displaced therefrom past thecheck valve 54 to the source of supply.

While this invention has been described in connection with certainspecific embodiments, the

principle involved is susceptible of numerous other applications thatwill readily occur to persons skilled in the art. The invention is,therefore, to be limited only as indicated by the scope of theappendedclaims.

Having thus described the various features of the invention, what Iclaim as new and desire to secure by Letters Patent is:

1. A fluid pressure actuated motor comprising a floating cylinder havinga small chamber and a relatively large chamber arranged in spacedrelation to one another, a passage connecting the chambers and an intakeport communicating with the passage, a piston reciprocable in each ofthe chambers, and a double end valve in the passage'normally open toestablish communication between the small chamber and the passage and toclose communication between the large chamberand the passage andoperative under a predetermined pressure to close communication betweenthe small chamber and the passage so as to trap 'fluidin the smallchamber and to establish communication between the large chamber and thepassage. v

2. A fluid pressure actuated motor comprising a floating cylinder'havinga small chamber and a relatively large chamber, a passage connecting thechambers and an inlet port communicating with'the passage, a pistonreciprocable in each of the chambers, and valve mechanism in the passageoperative upon attaining a predetermined pressure to close communicationbetween the small chamber and the passage so as to trap fluid in thesmall chamber and to establish communication between the large chamberand the passage.

3. A fluid pressm'e actuated motor comprising a shiftably mountedcylinder having a small chamber and a relatively large chamber, apassage connecting the chambers and a fluid inlet communicating with thepassage, a piston reciprocable in each of the chambers, and a fluidpressure actuated valve for control of the passage operative uponattaining a predetermined pressure to close communication between thesmall chamber and the passage so as to trap fluid in the small chamberand to establish communication between the large chamber and thepassage.

4. A fluid pressure actuated motor comprising a shiitably mountedcylinder having a small chamber and a relatively large chamber, apassage connecting the chambers and an intake port communicating withthe passage, a controlled passage between the intake port and the largechamber, a piston reciprocable in'each of the chambers, and a fluidpressure actuated valve for control of the passage connecting thechambers operative upon attaining a predetermined pressure to closecommunication between the small chamber and the passage so as to trapfluid in the small chamber and to establish communication between thelarge chamber and the passage.

5. A fluid pressure actuated motor comprising a shiftably mountedcylinder having a small chamber and a relatively large chamber and apassage connecting the chambers, an intake passage communicating withthe passage connecting the chambers, a controlled passage connecting theintake passage to the large chamber, a piston reciprocable in each ofthe chambers, and a springpressed fluid actuated double-end valve forcontrol of the passage connecting the chambers operative upon attaininga predetermined pressure to close the small chamber and. open the largechamber.

6. A fluid pressure actuated motor comprising a floating cylinderincluding a small chamber, a relatively large chamber arranged in spacedconcentric relation to the small chamber, a passage connecting thechambers, a fluid inlet communicating with the passage and a controlledpassage connecting the inlet with the large chamber, a pistonreciprocable in each of the chambers, a double-end valve in the passagehaving a part subjected to the initial pressure on the fluid in themotor tending to close communication between the small chamber and thepassage and to establish communication between the large chamber and thepassage, and another part subjected to pressure on the fluid in thesmall chamber upon closing the communication between the small.

chamber and the passage.

'7. A fluid pressure actuated motor comprising a floating cylinderhaving a. small chamber, a relatively large chamber, a passageconnecting the chambers, a fluid inlet communicating with the passageand a controlled passage connecting the inlet to the large chamber, apiston reciprocable in each of the chambers, a double-end valve in thepassage for control of communication between the small and largechambers with the passage, and a spring-pressed piston attached to thevalve and arranged in concentric relation to the piston complementary tothe large chamber and exposed to pressure in the large chamber.

HERBERT C. BOWEN.

